1. Field of the Invention
The present invention relates to a technique for handling film substrates when treating film substrates.
2. Description of the Related Art
In the field of packaging technology, high density packaging is required in association with miniaturization and improved high performance of electronic equipment. To achieve this, the connection of elements to a mount board has increased in minuteness, and packaging with greater reliability is required. A surface reforming method by plasma is one method of assuring reliability. For example, organic impurities adhering to the surface can be removed, the bonding strength of the wire bonding enhanced, the wettability improved, and the adhesion of sealing resin to the substrate increased with this plasma treatment. In other words, the substrate surface is activated by oxygen plasma, active oxygen and organic matter react to give a carboxyl group (xe2x80x94COOH), a carbonyl group (xe2x95x90Cxe2x95x90O), or the like, and a surface activating effect such as improving bonding strength, is generated. A surface cleaning effect is furthermore produced by sputtering action from argon ions or oxygen ions.
In particular, when oxygen remains on the substrate surface in a flexible circuit substrate comprising film or the like, the circuit may corrode due to the effect of moisture that surrounds the substrate and electricity that flows through the circuit, so chlorine adhering to the surface is removed by plasma treatment. The adhesion of resin and the substrate is also improved and the penetration of moisture from the exterior is prevented.
The conventional configuration of such plasma treatment is typified by manually performing a series of operations one step at a time by mounting several films in the chamber, closing the chamber lid, performing rough vacuum and main vacuuming, opening the gas valve, applying high-frequency power, stopping application of high-frequency power, restoring atmospheric pressure, and opening the chamber. Vacuum pressure is confirmed by a vacuum gauge, and the time high-frequency power is applied is measured with a stop watch.
However, the throughput is limited with the configuration described above because batch treatment becomes inevitable. In addition, the film is manually inserted and removed, and can therefore be contaminated. Film management is furthermore difficult due to time gap between cleaning and the following process.
In view of the above, a principal object of the present invention is to provide a technique for mounting and treating a film on an electrostatic stage, and automating the process.
The first invention is a film substrate treatment apparatus that comprises: a stage for holding a rear surface of the film substrate by electrostatic force, the rear surface being opposite to a to-be-treated surface of the film substrate; a chamber for accommodating the stage in an interior thereof; a treatment unit for performing a predetermined treatment on the to-be-treated surface of the film substrate held by the stage, with the interior of the chamber in a decompressed state; and a transport unit for transporting a film substrate while holding the to-be-treated surface thereof, and mounting the film substrate on the stage while pressing the to-be-treated surface thereof against the stage.
The second invention is the film substrate treatment apparatus according to the first invention, wherein the transport unit has a carrying-in holding unit that holds the film substrate by suction.
The third invention is the film substrate treatment apparatus of the first or second invention, wherein the carrying-in holding unit has a pressing member for pressing at least an edge portion area of the film substrate against the stage.
The fourth invention is the film substrate treatment apparatus of the first or second invention, wherein the carrying-in holding unit has a surface for pressing an entire peripheral portion of the film substrate against the stage.
The fifth invention is a film substrate treatment method that comprises: a transport step for transporting a film substrate while holding a to-be-treated surface of the film substrate by a carrying-in holding unit; a mounting step for mounting the film substrate on a stage while pressing the to-be-treated surface of the film substrate against the stage by the carrying-in holding unit; a stage holding step for holding a rear surface of the film substrate on the stage by electrostatic force, the rear surface being opposite to the to-be-treated surface; a decompressing step for reducing pressure in an area surrounding the stage; and a treatment unit step for performing a predetermined treatment on the to-be-treated surface of the film substrate.
The sixth invention is the film substrate treatment method according to the fifth invention, wherein the carrying-in holding unit presses at least the edge portion area of the film substrate against the stage in the mounting step.
The seventh invention is the film substrate treatment method according to the fifth invention, wherein the carrying-in holding unit presses the entire peripheral portion of the film substrate against the stage in the mounting step.
The eighth invention is the film substrate treatment method according to any one of the fifth to seventh inventions, wherein the stage holding step has a step for applying voltage to the stage, and a step for releasing the hold of the film substrate by the carrying-in holding unit after changing the voltage.
The ninth invention is the film substrate treatment method according to any one of the fifth to seventh inventions, wherein the stage holding step has a step for applying voltage to the stage, a current detecting step for detecting current to the stage and detecting a drop in current after applying the voltage, and a releasing step for releasing the hold of the film substrate by the carrying-in holding unit after detecting a drop in the current.
The tenth invention is a film substrate treatment apparatus having a carrying-out holding unit for dismounting a film substrate from a stage that holds the film substrate by electrostatic force, wherein the carrying-out holding unit comprises an edge lifting unit for holding and lifting an edge of the film substrate from the stage, and a complete separation unit for holding other parts of the film substrate and separating the entire film substrate from the stage.
The eleventh invention is the film substrate treatment apparatus according to the tenth invention, wherein the edge lifting unit comes into contact with the film substrate and is a part of a circular arc surface for sucking, and the complete separation unit is another part of the circular arc surface.
The twelfth invention is a film substrate treatment method for dismounting a film substrate from a stage for holding the film substrate, the film substrate treatment method comprising a holding step in which an edge lifting unit holds an edge of the film substrate on the stage, and a complete separation unit holds other parts; an edge lifting step in which the edge lifting unit lifts the edge of the film substrate from the stage by providing a clearance from the stage; and a complete separation step in which the complete separation unit completely separates the entire film substrate from the stage by providing a clearance from the stage.
The thirteenth invention is the film substrate dismounting method according to the twelfth invention, wherein the stage folds the film substrate by electrostatic force, and the method further comprises a voltage terminating step for terminating voltage applied to the stage, before the edge portion lifting step, and a voltage detection step for detecting change in voltage of the stage.
The fourteenth invention is the film substrate dismounting method according to the thirteenth invention, further comprising a reverse voltage applying step for providing reverse voltage to the stage, before the voltage terminating step.
The fifteenth invention is a film substrate treatment apparatus comprising a transport unit for transporting film substrates, a stage for holding a rear surface of the film substrate of the film substrate by electrostatic force, the rear surface being opposite to a to-be-treated surface of the film substrate, a chamber for accommodating the stage in an interior thereof, and a treatment unit for performing a predetermined treatment on the to-be-treated surface of the film substrate held by the stage, with the interior of the chamber in a decompressed state, wherein the transport unit comprises a carrying-in holding unit for holding and transporting the film substrates, and mounting the film substrate on the stage while pressing the to-be-treated surface of the film substrate, and a carrying-out holding unit for dismounting the film substrates from the stage that is holding the film substrate by electrostatic force.
The sixteenth invention is the film substrate treatment apparatus according to the fifteenth invention, wherein the carrying-out holding unit holds the film substrate by suction, and presses the edge portion area of the film substrate against the stage.
The seventeenth invention is the film substrate treatment apparatus according to the fifteenth invention, wherein the carrying-out holding unit first holds the edge portion of the film substrate and thereafter lifts the entire film substrate from the stage.
According to the film substrate treatment apparatus and method related to the present invention according to the configuration described above, a film substrate can be reliably held on a stage when the film substrate is processed in a decompressed atmosphere. According to the film substrate treatment apparatus and the film substrate dismounting method related to the present invention, the film substrate can be received from the stage holding the film substrate by electrostatic force, without application of excessive force.